Means for conveying powdery material in fine distribution, particularly for use in flash die casting



BIEL ET AL March 4, 1958 MEANS FOR CONVEYING POWDERY MATERIAL IN FINEDISTRIBUTION, PARTICULARLY FOR USE IN FLASH DIE CASTING 2 Shee'ts-S'neet1 Filed Feb. 20, 1956 March 4, 1958 v H. BIEL ET AL 2,825,605

MEANS FOR CONVEYING POWDERY MATERIAL IN FINE DISTRIBUTION,PARTICULARLYFOR USE IN FLASH DIE! CASTING Filed Feb. 20, 1956 2Sheets-Sheet 2 of x I 1! FEE-E NVENTORS. #4713 2 e 7 iv 71 W47;flz'zzfzzsa V/JZZ 77747 iaseZZe aim 3K3 United States Patent MEANS FORCONVEYiNG POWDERY MATERIAL IN FINE DISTRIBUTION, PARTICULARLY FOR USE INFLAH DIE (TASTING Hans Biel, Neuifen, Runwalt Kiihfuss, Metzingen, andWaldemar Raschke, Nani-fen, Germany, assignors to Hans Sicldnger,Providence, R. I.

Application February 2t 1956, Serial No. 566,725 Claims priority,application Germany February 22, 1955 8 Claims. (Cl. 302-36) Thisinvention relates to the conveying of powdery material in the so-calledflash die casting method and similar methods of applying layers of somematerial. In these methods, the powdery material should be conveyed tothe required apparatus in an exceedingly fine and uniform distribution.To this end, the material mixed with air in a certain ratio is eductedfrom a container in which it is subjected to a whirling motion. In knowndevices, the material is whirled up either by a stream of gas or by suchmechanical means as turning of the container. These means are howeverinsufiicient. In some cases, the material when mixed with air in acertain proportion is whirled up insufficiently; in others, powdergrains are screened out so that the finer particles are educted first.In most cases, a considerable remainder is left behind in the container,which is no longer educted.

It is an object of the present invention to provide a conveyor forpowdery material which overcomes the disadavntages of previously knowndevices and is economical to fabricate, efiicient in operation and ofversatile use. Other objects will be apparent from the followingdescription and claims.

Under the present invention, a drum of generally known constructioncontaining the material is connected with a rotary drive on a horizontalaxis. Inwardly pointing blades are arranged inside the drum in such amanner that during rotation of the drum, filled to less than one halfwith material, the material is carried by the blades upwardly in thedirection of rotation and after passing above the horizontal axial planewill drop downwardly from between the blades and fall back into theeffective range of a suction point located within the drum. Through thissystem the above defects of previously known devices can be eliminated.The powdery material is thus whirled up in an even and vigorous manner,independent of the quantity of suction air. All grains of the materialare simultaneously and uniformly seized by this whirling motion. Thematerial contained in the container can be educted completely as eventhe smallest quantities will be seized and lifted by the blades.

To suit the specific nature of the material, different controlarrangements may be provided. Thus, the stationary suction pipe, whichprojects through a sealed aperture coaxial with the drum shaft and isprovided within the drum with one or more suction slits, may berotatably adjustable independent of the drum, so that the position ofthe suction slits may be varied in relation to the dropping materialcloud. Moreover, the rotary drive of the drum may be provided with aninfinitely variable speed gear so that the drum speed may be varied.Finally, the position of the blades may be adjustable within the drum.

It is another advantageous operational feature of the apparatus of thisinvention that the drum, together with its drive, is incorporated in aframe preferably made of tubing, thus providing a portable structure, sothat the drum may be set up either for horizontal operation or,

2,825,605 Patented Mar. 4, 1958 optionally, for vertical operation so asto be fed through a detachable cover located on the face side oppositethe drive.

A preferred embodiment of the invention is described in detail with theaid of attached drawings, in which:

Figure 1 represents a side view partly in cross section of the apparatusin its operational position;

Fig. 2 is a cross-sectional view taken along the line 2-2 of Fig. l andshowing the arrangement of blades within the drum;

Fig. 3 is a front view of the apparatus taken in the direction of arrow3 of Fig. 1 and showing suction tube adjusting means;

Fig. 4- is a detail view of a portion of the belt drive taken along theline 4-4 or Fig. 1;

Fig. 5 is a side view of the apparatus in its operational position,showing the side opposite that of Fig. 1;

Fig. 6 is a fragmentary view of the device in the feeding position withdetached cover and suction pipe holder; and

Figure 7 is a fragmentary side elevational view showing a modified formof invention which incorporates angularly adjustable blades.

The receptacle for the powdery material is a cylindrical drum it whichmay be closed at its open end with a cover 2. Cover 2 can be locked inits closed position with the aid of quick-action toggle levers 3 ofknown design which are located at the drum edge. A flanged shaft 3 isfixed to the bottom of drum 1 opposite cover 2 to serve as a rotatablesupport.

Drum I, together with its drive, is carried by a frame 5 consisting ofwelded tubes. The drum drive is accommodated in and supported by ahousing 6 that extends across nearly half of frame 5 and which is formedby sheet metal Walls fastened between the tubes of frame 5 (one wallbeing removed in Figure 1 for illustrative purposes). For the drive ofdrum 1 an electric motor 7 is provided which, in the present embodimentof the invention, is positioned at the outer face wall of housing 6.Drum shaft 4 is mounted in a bearing 8 forming part of a gear case 9located at the front end of housing 6 opposite motor 7. The free end ofdrum shaft 4 projecting from hearing 8 within housing 6 carries a wormwheel It) which meshes with a worm on shaft 11 mounted in gear case 9.Worm shaft 11 is connected to a shaft 14, which is also mounted in gearcase 9, by means of a pair of spur gears l2, 13 within gear case 9.Between shaft I4 and motor 7 a back gear shaft 15 is provided which isdriven by V-belt drive 16 from the motor and which drives shaft 14 byanother V-belt. Gear 13 may be dis placed on shaft 14 by means of ashiftable lever 18 in such a manner as to be brought out of mesh withgear 12 of worm shaft 11, thus interrupting the driving connectionbetween motor 7 and drum 1. Thus the drum may be clutched with thedrive, in the present embodiment, with the aid of control lever 18projecting through a slot in the outer front wall of housing 6.Similarly, the clutch could be incorporated in a variable speed gearoperable by lever 18.

Back gear shaft 15 is mounted between motor 7 and gear case 9 on arocking lever 19 which may be adjusted by means of a rod 20 and crank 21operated by a control knob 22 located on a side wall of housing 6. Thetwo V-belts 16 and 17 are passed between V-belt pulleys 23, 24 and 25mounted on shaft 15, the central pulley 24 being provided with inclinedfaces on either side and sli-dably mounted on back gear shaft 15. As aresult, an infinitely variable transmission is obtained between themotor shaft and the coupling shaft. If lever 19 is moved by means ofcontrol knob 22, for instance in the direction of arrow 26 in Figure 1,the distance between back gear shaft 15 and the motor shaft increaseswhile that between the back gear shaft and coupling shaft 14 decreases.Therefore central V-belt pulley 24 is displaced axially in such a mannerthat the motor belt 16 is pulled down deeper between V-belt pulleys 23and 24 so as to run on a smaller diameter, while the second belt 1'7between V-belt pulleys 24 and 25 is moved outward onto a largerdiameter. As a result, the transmission ratio between motor 7 and drum1, is changed so that the drum speed is increased. To start and stopmotor 7, a switch 27 is provided on the same side of housing 6 on whichknob 22 for the speed control is located. On the same side of housing 6a current supply line 28 is introduced.

The inside wall of drum 1 is provided with a plurality of blades 29which, in the present embodiment, are arranged in a radial system(Figure 2). These blades 29 are preferably attached to a hollow cylinder30 fitted into the drum, and extend the entire length between drumbottom and cover 2. if required, the blades may be linked with the shellof the drum or cylinder 30 and rendered angularly adjustable withrespect to the drum shell by means of a ring movably mounted at eitherface side.

Figure 7 shows a modified form of the invention which incorporatesangularly adjustable blades. In this figure, a drum 44 is shown having acover 45 at one end, a hollow cylinder 46 being disposed within thedrum. Fixed to the interior of cylinder 46 are a plurality of pairs oftrunnions 47, said trunnions being located at opposite ends of thecylinder. Between each pair of trunnions, a blade 48 is pivoted forrocking movement by means of pins 49 extending from the ends of theblades. A longer pin 51 is attached to one end of each blade and extendsinto a slot 52 in a ring 53, this ring being disposed at one end ofcylinder 46 and being held in position by an annular spacing member 54.Ring 53 is provided with a plurality of slots 52, a pin being disposedwithin each slot. it will be apparent from an examination of Figure 7that, by rotatably adjusting ring 53, the angular positions of blades 48may be simultaneously altered.

Coaxially with drum 1, a tube 31 projects through a bore in drum cover2, being sealed to the drum cover so that rotation is permitted butaxial movement is prevented. The portion of tube 31 located within drum1 is closed at its free end While its shell is provided with one or moreslots 32. The end of tube 31 located outside cover 2 is adapted to beconnected with a preferably fiexible suction conduit 33. Between theconduit end and cover 2, a swinging arm 34 is arranged on tube 31, inwhich a set screw 35 is mounted parallel to the drum shaft. By means ofthis set screw 35, tube 31 can be fastened to a holding device connectedwith frame 5. The holding device is equipped with a ring 36 surroundingtube 31 which ring is provided with teeth to receive the point of setscrew 35. For locking on frame 5, ring 36 is provided with radial arms37 having bores at their ends to fit over studs 38 projecting from thetubes of the front structure of frame 5. By tightening set screw 35,tube 31 is thus locked with frame 5. Tube 31 can be adjusted by turningarm 34 and displacing set screw 35 on holder ring 36 to any desiredposition with respect to cover 2 or drum ll, thus enabling the positionof the slots 32 in tube 31 to be changed within the drum. To introducetube 3?: into holder ring 36, the latter has been provided with aslotted aperture 39 (Figure 3) on its circumference.

Tubular frame is constructed as a supporting structure of portable type.To this end, it is provided with handles 40 located on the face sidenear drum cover 2. On its opposite side a kind of handle is provided(41) by the shape of housing 6. The longitudinal sides of tubular frame5 are designed as undercarriage skids.

To feed the powdery material, the apparatus is set up in the verticalposition shown in Figure 6 so that the open front side of drum 1 thatmay be closed with cover 2 is pointing upward. After holder 36, 37 andcover 2 have been removed, the drum may be fed from above. The powderquantity to be fed into the drum should not exceed one half of the drumspace with loose density, so that the bulk remains below the drum shaft(Figure 2) while the drum is in its horizontal position. After the drumhas thus been charged and cover 2 and holder 36, 37 have been replaced,the apparatus is brought, for instance, into the position illustrated inFigure 5 so that the drum assumes a horizontal position. Now motor '7 isstarted by means of switch 27. The clutch 12, 13 is engaged by means ofhand lever 13 so that the drum revolves. By turning knob 22, the speedof the drum may be adjusted. Suction tube 31 is brought into its properposition in which it will be locked by means of set screw 35 located onholder 36, 37 and finally is connected with the suction system.

As the drum revolves, a part of the powdery material is always carriedupard in the sense of rotation, and will then slide down, while in thedrum section above the horizontal axial plane, by its own weight, frombetween blades 29 and drop back into the lower drum section. Thedropping material will form a fine cloud of material, part of which willbe educted through slots 32 in suction tube 31. As blades 29 will seizethe material even when the container is almost empty, completeconveyance of the material is produced under constantly uniformconditions. Through adjustment of the drum speed, positioning of suctionslots 32 on suction tube 31, and, in case of need, adjustment ofinclination of blades 29, the specific requirements of the individualmaterial can be fully met with. in the present embodiment, blades 29 arearranged parallel to the drum shaft. They could however be arranged atan angle to the dum shaft, i. e., in a helical or spiral manner.

As the material is conveyed through the air, provision must be made foradmission of air into the drum. For this purpose, the drum is providedin a suitable place with a bore (not shown). This bore is preferablymade on the face side of the drum opposite cover 2. In order to ensurethat air penetrates the drum and to prevent leakage of material throughthis bore, the latter is suitably covered with a fine screen.

The pressure within the drum may be adjusted by the provision of one ormore apertures in suction tube 31 outside the drum, each of which shouldbe capable of being completely or partially closed by a screw 43 asshown in Figure 6. As these apertures may be closed gradually, the rateof admission of outside air into the suction tube is adjustable and willdepend on such factors as the material graining, intensity of pressurein the drum and the specific gravity of the powdery material.

While it will be apparent that the preferred embodiment of the inventiondisclosed is well calculated to fulfill the objects above stated, itwill be appreciated that the invention is susceptible to modification,variation and change without departing from the proper scope or fairmeaning of the subjoined claims.

What is claimed is:

l. A device for conveying powdery material in fine distribution,comprising a drum, means supporting said drum for rotation on ahorizontal axis, drive means for rotating said drum, a plurality ofinwardly projecting blades extending along the inner surface of saiddrum, said blades being so arranged as to carry material upwardly in thedirection of rotation of said drum which material may drop from betweenthe blades to form a cloud, a suction tube connected to the interior ofsaid drum to draw off the cloud of powdery material, said suction tubehaving a cylindrical outer surface and extending a substantial distanceinto said drum coaxially thereof, and a plurality of openings in saidcylindrical surface along the portion of said tube within said drum.

2. A device for conveying powdery material in fine distribution,comprising a drum, means supporting said drum for rotation on ahorizontal axis, drive means for rotating said drum, a plurality ofinwardly projecting blades extending along the inner surface of saiddrum, said blades being so arranged as to carry material upwardly in thedirection of rotation of said drum which material may drop from betweenthe blades to form a cloud, a tube of cylindrical shape extendingcoaxially through one end of said drum into the interior thereof, a sealbetween said tube and said drum end, means for connecting the outer endof said tube to a source of suction, and an opening in the cylindricalsurface on the inner portion of said tube, whereby the cloud of powderymaterial may be educted through said tube.

3. The combination according to claim 2, said tube opening comprising aslot in the wall of said tube, and means mounting said tube forrotatable adjustment independently of the position of said drum, wherebysaid slot may be angularly adjusted with respect to the cloud of powderymaterial.

4. A device for conveying powdery material in fine distribution,comprising a drum, means supporting said drum for rotation on ahorizontal axis, drive means for rotating said drum, an infinitelyvariable transmission gearing included in said drive means, a pluralityof inwardly projecting blades extending along the inner surface of saiddrum, said blades being so arranged as to carry material upwardly in thedirection of rotation of said drum which material may drop from betweenthe blades to form a cloud, a suction tube connected to the interior ofsaid drum to draw off the cloud of powdery material, said suction tubehaving a cylindrical outer surface and extending a substantial distanceinto said drum coaxially thereof, and a plurality of openings in saidcylindrical surface along the portion of said tube within said drum.

5. A device for conveying powdery material in fine distribution,comprising a drum, means supporting said drum for rotation on ahorizontal axis, drive means for rotating said drum, a plurality ofinwardly projecting blades extending along the inner surface of saiddrum, said blades being so arranged as to carry material upwardly in thedirection of rotation of said drum which material may drop from betweenthe blades to form a cloud, means for adjusting the inclination of saidblades with respect to the drum surface, and a suction tube connected tothe interior of said drum to draw off the cloud of powdery material.

6. A device for conveying powdery material in fine distribution,comprising a rectangular frame, a fiat supporting portion at one end ofsaid frame, a second fiat supporting portion on one side of said frame,whereby the frame is capable of standing upright or resting on its side,a drum mounted within one portion of said frame, means supporting saiddrum for rotation on an axis parallel to the length of said frame, aremovable cover on said drum adjacent the end of said frame oppositesaid first flat supporting portion, drive means mounted within anotherportion of said frame for continuously rotating said drum, a pluralityof inwardly projecting blades extending along the inner surface of saiddrum, said blades being so shaped as to carry powdery material upwardlywithin said drum in the direction of rotation of the drum and permittingsaid material to drop back so as to form a cloud, and a suction tubeconnected with said drum interior for educting said material cloudtherefrom, the arrangement of said parts being such that said drum maybe charged when said frame is standing in its upright position and saidmaterial may be educted when said frame is resting on its side.

7. The combination according to claim 6, said suction tube extendingcoaxially through said cover, and means for adjustably securing saidtube in selected angular positions, comprising a holder secured to saidframe and concentric with said tube axis, a radial arm on said tube, andmeans for adjustably securing said arm to said holder.

8. A device for conveying powdery material in fine distribution,comprising a drum, means supporting said drum for rotation on ahorizontal axis, drive means for rotating said drum, a plurality ofinwardly projecting blades extending along inner surface of said drum,said blades being so arranged as to carry material upwardly in thedirection of rotation of said drum which material may drop from betweenthe blades to form a cloud, a tube having a cylindrical outer surfaceextending coaxially through one end of said drum into the interiorthereof, a seal between said tube and said drum end, means forconnecting the outer end of said tube to a source of suction, an openingin said cylindrical surface on the inner portion of said tube, wherebythe cloud of powdery material may be educted through said tube, apressure-regulating aperture in said tube connected to the atmosphereoutside said drum, and an adjustable restriction for said aperture,whereby the degree of suction may be varied.

References Cited in the file of this patent UNITED STATES PATENTS995,422 Clarke June 13, 1911 1,686,256 Royle Oct. 2, 1928 2,471,314Curtis May 24, 1949 2,503,170 Plos Apr. 4, 1950

